Horst Mahler, a founding member of the Red Army Faction in 1970, is accused of regularly posting documents online between 2001 and 2004.

Denial of the Nazi Holocaust is a crime in Germany. Mahler has been charged with incitement and faces up to five years in prison if convicted.

The Potsdam state court trial is the latest case against the 72-year-old attorney, who was sentenced to 11 months in prison in July last year for giving the stiff-armed Nazi salute when he reported to prison after a conviction in a separate case.

In addition to several neo-Nazi related convictions, a court in Mainz in 2003 found Mahler guilty of condoning a crime for saying the Sept. 11, 2001 attacks in the United States were justified and fined him several thousand euros (dollars).”

He was also convicted in the mid-1970s for RAF related activities — including several bank robberies and for helping notorious terrorist Andreas Baader, another founding member of the group, to escape from jail.

He was sentenced to 14 years in prison but was released in 1980 after he made several public statements condemning terrorism and Red Army Faction methods.

Mahler then joined the far-right National Democratic Party, from 2000 to 2003, and acted as its attorney. The Potsdam trial is expected to last until at least mid-November.